Field of the Invention
The field of the invention relates to a dispensing device.
Brief Description of the Related Art
This disclosure teaches a liquid handling device, which is used, for example, in a diagnostic system for the dispensing of liquids into an analytical device. Known issues related to current liquid handling devices are a large dead volume of liquid within the liquid dispensing device which results in wasted fluid trapped in the dead volume. The fluid in the liquid dispensing device may also be instable due to the presence of ambient gasses that can lead to degradation of the liquid. There may also be an issue associated with confusion by the operator between the bottles and the tubing lines on prior art devices. There are also issues related to collection of debris on injector nozzles in the prior art devices, which can accumulate over time and lead to false results or result in malfunction.
Current diagnostic systems have a liquid handling device, which comprises a bottle containing consumable fluids, an aspiration line connected to an outlet of the bottle, and a dispensing pump with a dispense line connected to an injection nozzle. The bottle is the sole consumable part in the liquid handling device. All of the other components are integrated within the diagnostic system and can only be replaced with some difficulty.
One example of a prior art device is known from US patent application publication No. US 2013/0092288 (Schriber, assigned to Tecan Trading). This patent application teaches a dispenser for delivering flowable or pourable material from a container to an outlet end of the line. The liquid handling device shown in this patent application has a long tube with large dead volumes between the bottle and the injection nozzle, which as noted above comprises wasted fluid volume with associated costs of the wasted fluid.
A further example of a liquid handling device used in the art is a pipetting system. Such pipetting systems are known, for example, from United States patent application publication No. US 2008/0019878 (Trump, assigned to Stratec Biomedical Systems AG). This US patent application teaches a positioning device provided for positioning pipettes in a diagnostic device.
The European Patent Application EP 2 481 480 A1 discloses an apparatus including a fluid reservoir and a compressible metering chamber including a first end coupled to the fluid reservoir and a second end. The apparatus further includes a valve coupled to the second end of the metering chamber and a nozzle coupled to the valve. A compressive force is applied to the metering chamber to eject a predetermined amount of fluid. When the compressive force is removed, the metering chamber is refilled.
The UK Patent Application GB 2 416 757 A discloses an apparatus for dispensing a flowable foodstuff. The apparatus comprises a reservoir. Two non-return valves lead into and out of a chamber, and a pump piston is moveable within the chamber to vary the size of the chamber. The piston does not comprise a volume which can be filled with fluid because the piston together with the piston shaft simply adjust the volume of the chamber which is in turn filled with fluid. This apparatus also has a long tube with large dead volumes between the reservoir and the injection nozzle, which as noted above comprises wasted fluid volume with associated costs of the wasted fluid.
Many of the chemicals dispensed in the fluid may be sensitive to air, or other gases, and so the stability of the fluid may be limited if an open bottle or other container is used. On the other hand, an open bottle is often used in order to avoid the need to reduce the pressure above the fluid during removal of the fluid out of the bottle. Such liquid dispenser devices may further require additional air-inlet filters to filter any incoming gases and to avoid degeneration of the fluid in the bottle. These air-inlet filters add to the costs of the diagnostic devices.
The use of the consumable bottles, in particular those with the same shape for different fluids, brings a further problem of the correct placement of the individual aspiration line to the correct bottle. Even in those cases in which the user identifies the bottle and the correct aspiration line, experience has shown that mistakes may occur which lead either to incorrect results or contamination of the liquid handling device. The contamination of the system may require intensive cleaning to enable the system to be reused.